The case for tocolysis in threatened preterm labour

Fisk, Nicholas M. and Chan, Jerry (2003) The case for tocolysis in threatened preterm labour. BJOG: An International Journal of Obstetrics & Gynaecology, 110 S20: 98-102. doi:10.1016/S1470-0328(03)00052-1

Author Fisk, Nicholas M.
Chan, Jerry
Title The case for tocolysis in threatened preterm labour
Journal name BJOG: An International Journal of Obstetrics & Gynaecology   Check publisher's open access policy
ISSN 1470-0328
Publication date 2003-04-01
Year available 2003
Sub-type Article (original research)
DOI 10.1016/S1470-0328(03)00052-1
Open Access Status Not yet assessed
Volume 110
Issue S20
Start page 98
End page 102
Total pages 5
Place of publication London
Publisher Blackwell
Language eng
Subject 111402 Obstetrics and Gynaecology
1114 Paediatrics and Reproductive Medicine
Formatted abstract
The failure of tocolytics to improve neonatal outcomes in placebo-controlled trials has wrongly been interpreted as evidence that they do not work. While delivery is unequivocally prolonged by 24 hours, 48 hours and 7 days, the time gained was not exploited to optimise neonatal outcome. These trials typically studied women at relatively advanced gestational ages with predictably good outcomes, enrolled them in tertiary centres where they could not benefit from in-utero transfer, and had low levels of corticosteroid administration. No study has been powered to detect clinically meaningful differences that might be expected to accrue from 1–7 days prolongation of gestation. Despite this, Bayesian interpretation suggests that tocolytics do improve neonatal outcome. The largest placebo-controlled study showed clear trends towards better survival in fetuses <28 weeks, lower rates of cerebral palsy and higher Bayley mental scores. Meta-analysis of neonatal morbidity in the beta-agonist trials suggests a near-significant reduction in respiratory distress syndrome (RDS), together with trends towards reduced intraventricular haemorrhage, necrotising enterocolitis, and patent ductus arteriosus. Finally, there is the Orwellian analogy that tocolytics don't work, but some work better than others. Although calcium antagonists have not been evaluated against placebo, meta-analysis of comparative trials with beta-agonists demonstrate a significantly lower incidence of RDS and neonatal jaundice, presumably mediated through the reduced chance of delivery within 48 hours and 7 days. Development of tocolytics that are safe for mother and baby should facilitate adequately-powered placebo-controlled studies, which both focus on women most likely to benefit and capitalise on the 1–7 days gained.
©RCOG 2003 BJOG: an International Journal of Obstetrics and Gynaecology.

Keyword Tocolytics
Placebo-controlled trials
In-utero transfer
Respiratory distress syndrome
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown
Additional Notes Published Online: 22 Dec 2003

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
School of Medicine Publications
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Citation counts: TR Web of Science Citation Count  Cited 11 times in Thomson Reuters Web of Science Article | Citations
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Created: Mon, 23 Mar 2009, 23:00:54 EST by Maria Campbell on behalf of Faculty Of Health Sciences